Esters of dicarboxylic acids and polyhydroxy tertiary amines as new detergent softener compounds

ABSTRACT

Novel esters of dicarboxylic acids and polyhydroxy tertiary amines having the structural formula:   wherein R1 is a monovalent hydrocarbon radical of 8 to 24, preferably 10 to 20 carbon atoms; R2 is an C1-C6 alkyl or alkylol radical containing 2 to 6 carbon atoms, and R3 is an alkylol radical containing 2 to 6 carbon atoms. The reaction mixture consists of mono-, di-, and/or tri-esters depending on the number of reactive hydroxyl groups in the alcoholamine and the amount of dicarboxylic acid utilized. These novel esters and salts thereof uniquely possess both detergency and softening properties.

United States Patent [191 Sundby 11] 1 3,927,073 Dec. 16, 1975 ESTERS OFDICARBOXYLIC ACIDS AND POLYHYDROXY TERTIARY AMINES AS NEW DETERGENTSOFTENER COMPOUNDS Inventor: Bjorn Sundby, Piscataway, NJ.

Colgate-Palmolive Company, New York, N.Y.

Filed: Oct. 24, 1973 Appl. No.: 409,027

Related US. Application Data Assignee:

References Cited FOREIGN PATENTS OR APPLICATIONS 5/1967 France 260/475 PPrimary ExaminerLorraine A. Weinberger Assistant ExaminerE. Jane SkellyAttorney, Agent, or FirmSteven J. Baron; Norman Blumenkopf; Herbert S.Sylvester [57] ABSTRACT Novel esters of dicarboxylic acids andpolyhydroxy tertiary amines having the structural formula:

wherein R is a monovalent hydrocarbon radical of 8 to 24, preferably 10to 20 carbon atoms; R is an C -C alkyl or alkylol radical containing 2to 6 carbon atoms, and R is an alkylol radical containing 2 to 6 carbonatoms. The reaction mixture consists of mono-, di-, and/or tri-estersdepending on the number of reactive hydroxyl groups in the alcoholamineand the amount of dicarboxylic acid utilized. These novel esters andsalts thereof uniquely possess both detergency and softening properties.

3 Claims, No Drawings pounds are useful surface active agents and aresub- 1 stantive to a variety of fibrous materials. Thus, they may beused as emulsifiers, solubilizing agents for lipophilic materials,wetting agents, detergents and softeners for textiles and hair.

Since the introduction of commercial synthetic organic detergents andemulsifiers to replace the conventional watersoluble higher fatty acidsoaps, much research work has been performed in an effort to improvesuch compounds and compositions including them, with the object ofobtaining better and more convenient laundering of textiles. As aresult, a wide variety of types of surface active agents and detergentshave been produced and many such compositions have been manufacturedcommercially and have been introduced to the market place. As betterproducts were made, the goals set for researchers on detergency wereincreased and the properties of the desired products were such as tohave been thought impossible of attainment only a few years before.Although the cleaning function of surface active materials is still veryimportant and products which clean better than competitive compounds arealways in demand, additional attributes of cleaning compounds weredesired. For example, with the increasing importance of cold waterwashing, detergent compositions were desired which would be capable ofsuccessfully cleaning and whitening textiles and laundry in cold water,as well as in hot water. Such washing capability is of importance inmaking a product acceptable for the washing of wool and othershrink-sensitive materials. In addition, softening agents have beenfound to be a desirable and in some instances, a necessary ingredient inthe washing of textiles. However, because of the incompatibility ofsofteners and detergents, it has been necessary to utilize the textilesoftener in the final rinse as a separate step in a washing cycle. Theobjections to this procedure are obvious; one must be present during thewashing cycle and few washing machines include devices for the additionof softeners in the final rinse.

Therefore, it has been the long desire of the detergent industry toprovide a single compound possessing the foaming and detergencycharacteristics of conventional detergents yet, uniquely possessingfabric softening ability. Such a single compound uniquely possessingboth detergency and fabric softening ability would of course eliminatethe disadvantages of employing two separate materials and in addition,would completely eliminate the disadvantages associated with theincompatibility of conventional anionic detergents and cationis fabricsofteners.

The present invented compounds have the combined properties ofdetergency and textile softening. They possess detergent activity inboth hard and soft waters and at both elevated and lower temperatures.In addition, these compounds are excellent in textile softeningactivity. Such an activity evidences a high degree of substantivity,which is unexpected in a surface active 2 material which itselffunctions to release adsorbed and absorbed substances from materialsbeing washed.

In accordance with the present invention, there are provided novelesters of dicarboxylic acids and 2- hydroxyalkyl tertiary alcohol aminesand salts thereof consisting predominantly of the mono-ester having theformula:

which are effective detergents and which also serve to soften fibrousmaterials when applied to them, as in aqueous solution. In the formula,R is a monovalent hydrocarbon radical of 8 to 24 and preferably 10 to 20carbon atoms, R is an C -C alkyl or alkylol radical of 2 to 6 carbonatoms, R, is a divalent hydrocarbon radical of 2 to 6 carbon atoms (R =ROH); R is a saturated, unsaturated, aliphatic or aromatic divalent-hydrocarbon radical (residue of the dicarboxylic acid), X is hydrogenor a salt-forming element or radical. If X is an element it is preferredthat it should be an alkali metal such as potassium, sodium and lithiumor other suitable salt-forming metal, capable of making the compoundswater soluble. If X is a radical it is preferred that such be ammonium,alkylamine or alkanolamine, either mono-, di-, or tri-alkylamine ormono-, dior tri-alkanolamine, in which the alkyl and alkanol groups ofthe salt-forming amines are of 1 to 4 carbon atoms, preferably 2 to 3carbon atoms.

The novel esters of the present invention are prepared by reacting thedicarboxylic acid or preferably the anhydride thereof with a polyhydroxytertiary amine having the structure:

wherein R is a monovalent hydrocarbon radical of 8 to 24 and preferably10 to 20 carbon atoms, R is an C -C alkyl or hydroxyalkyl radicalcontaining 2 to 6 carbon atoms, R is a hydroxy alkyl radical containing2 to 6 carbon atoms. Examples of radicals of this class are:

and related compounds in which the radicals contain more carbon atomsthan in the formula shown above, e.g., radicals of di(isopropanol)amine,N-methyl-N-iso- OH H CH OH heat ' CH CH OH ca, HN

The dicarboxylic acid may be saturated, unsaturated, substituted orunsubstituted aliphatic or aromatic and include phthalic, succinic,maleic, glutaric, tartaric, malic, adipic, diphenic, naphthalic, etc.

The reaction is predominently in accordance with the following equation:

wherein the R radicals are as aforedefined, and equimolar amounts ofreactants are used. The alcoholamine has at least two hydroxyl groups,one in the long chain resulting from the epoxide ring opening and one ormore from the original alcoholamine. When utilizing equimolar amounts ofreactants, the primary hydroxyl is preferentially esterified into themono-ester, since it is the least stearically hindered and therefor themost reactive group. However, when more than one mole of the acidanhydride is used, the other hydroxyl radicals react to form thedi-ester, tri-ester, etc. and mixtures thereof. Similarly, the number ofhydroxyl groups in the alcoholamine is determinative of the formation ofthe mono-, di-, or triesters.

4 The esters formed in accordance with instant invention have one freecarboxyl group for every esterified carboxyl radical as shown by thefollowing structural formulae:

mono-ester:

di-ester:

CH,CH2OH Ol' OCR5COOH R,- CH2NR4OOCR,,COOH

tri-ester:

OOCRSCOOH R, -CH2 R4-OOCR5COOH RZOOCRSCOOH The esterification of the2-hydroxyalkylalcoholamines with the dicarboxylic acid anhydride is anexo-.-

thermic reaction which can be carried out in aprotic solvent, ether,chloroform or acetone, but it can also be carried out neat. The lattermethod is preferable as an industrial process, since no solvent isinvolved. The powdered acid anhydride (e.g. maleic anhydride) is addedgradually to the liquid alcoholamine which is held at a temperature ofabout C. The product is obtained as a high viscosity melt, that rapidlysolidifies upon cooling. The ester (e.g. maleate) may be con-. verted tothe alkali metal salt (e.g. sodium) by neutralizing with a diluteaqueous solution of alkaliv metal hydroxide such as a 10% NaOH. Whenutilizing a sol vent, the reactants are first dissolved therein and thesolution refluxed until the esterification has taken place. Evaporationof the solvent yields a resin-like waxy product, insoluble in water, butreadily soluble in mono, di-, and

triesters mono-, di-esters monoand di-esters :0 a dilute aqueous sodiumhydroxide solution.

When utilizing the dicarboxylic acid in lieu of the anhydride, thereaction is controlled so that only one mole of water is removed permole of alcohol. Termination of the reaction at this point ensures theforma tion of the esters of instant invention and prevents theproduction of a polymeric linear ester. The reaction may be controlledby conventional methods of cooling or by other suitable means.

The products obtained are usually yellow or light yellow viscous mono,di, tri-esters and mixtures thereof, resin-like in appearance, insolublein water, but readily soluble in alcohol, acetone, chloroform and indilute aqueous sodium hydroxide wherein the sodium salt of the ester isformed. The mono-, diand tri-esters can be readily separated andpurified by chromatographic techniques in the usual manner. The sodiumsalts of instant novel esters are homogeneous and very water soluble,whereas the sodium salts of the" esters of secondary amines anddicarboxylic acids are less homogeneous and less water-soluble.Consequently, instant esters and salts thereof have been found to beparticularly useful as detergents, due to their combined property ofdetergency and fabric conditioning (softeningianti-static, etc.).

Examples of esters in accordance with the present invention include:

N-(Z-hydroxydodecyl)-methylethanolamine maleateN-(Z-hydroxyoctadecyl)-methylethanolamine maleate N-(Z-hydroxydodecyl)diisopropanolamine maleate N-( 2-hydroxyoctadecyl) diisopropanolaminemalea te N- (2-hydroxydodecy1)-diethanolamine maleateN-(2-hydroxyoctadecyl) diethanolamine maleate vN-(2-hydroxydodecyl)-diglycolarnine maleateN-(Z-hydroxoctadecyl);diglycolamine maleateN-(2-hydroxypentadecyl)-diethanolamine phthalate N-(2-hydroxyoctadecyl)die'thanolamine phthalatel...

The novel esters of the present invention, in addition to possessingexcellentdetergency and water softening properties, have been found tobe-compatible with the various detergent builders and other additivesconventionally employed in detergent compositions. Accordingly, it ispossible to formulate a detergent composition based upon the tertiaryalcohol amine-dicarboxylic acid ester as the detergent and watersoftener.

Various embodiments of the present invention will now be illustrated byreference to the following specific examples. It is to be understoodhowever that such examples are presented for purposes of illustrationonly and the present invention is in no way to be deemed as limitedthereby.

EXAMPLE 1 Preparation of N-(2-hydroxyhexadecyl)-diethanolamine maleate:

35 grams (0.1 mole) of N-(2-hydroxyhexadecyl)-diethanolamine was meltedand heated to 100C. 1 1 grams (0.11 mole) powdered maleic anhydride wasadded gradually to the hot melt with vigorous agitation. The

6 reaction mixture became at once very viscous with a clear yellowcolor. The mix-ture was heated to the melting point and then cooled. Theproduct solidified to a semi-solid yellow material with a pleasant odor,readily soluble in alcohol, acetone and chloroform.

EXAMPLE 2 1 Preparation of sodium maleate of N(2.-hydroxyhexadecyl)-diethanolamine:

OH C H CH OH The maleate prepared in accordance with Example 1 is cooledto about C and then neutralized with 10% sodium hydroxide.

EXAMPLE-:3

Preparation of. N-( 2-hydroxyhexadecyl)-diethanola mine phthalatez 30gr. of N( 2-hydroxyhexadecyl)-diethanolamine and 12.9 gr. phthali'canhydride (0.087'moles of each) were dissolved in m1 acetone',and thesolution was refluxed'for-two hours. The acetone was removed byevaporation, leaving a resin-like light yellow waxy material insolublein'water. i

EXAMPLE 4 Preparation of sodium'phthalate of N-( 2hydroxyhexadecyl)-diethanolamine:

on cH,cH,o|-i

COONa Three Spangler soil swatches were washed 10 minutes inTerg-O-Tometer, followed by a 5 minute rinse.

Similarly the test for softening effect on cotton materials is run usinga terry cloth towel in three gallons of 100 ppm. hardness water. Afterwashing in a miniature washing machine, the towel is rinsed in thenormal manner and dried. The softness is rated on a scale of 1 to 10,with 1 indicating no softness and 10 representing maximum softness.

Table l ARd (Soil Removal) Softness 7 F I20F Compound NB-TAP SOOPPMNB-TAP 300 PPM 1. Ester of N-(Z- y y is-ui alkyl )-diethanol- 1 amineand maleic anhydride, Na-salt 14.2 12.0 15.6 9.8 2. Ester of N-(2- Ihydroxy C alkyl )-diethanolamine and phthalic anhydride, Na-salt 17.6 11.5 16.8 12.5 9 3. Control-Linear tridecyl benzene sulfonate (LTBS) 17.011.0 19.2 13.1 1 4. Product of 18.0 1 1.7 20.4 12.8

Example 3 5. Control LTBS 16.2 9.9 21.0 12.2

and The results shown above lndlcate an unexpectedly excellentdetergency in hard and soft water, both cold 0 and hot, as compared tocommercial detergent linear AC fi tridecyl benzene sulfonate. Inaddition to possessing excellent detersive properties, instant estersexhibit (B) excellent fabric softening characteristics, not possessed bythe control. Similar results are obtained with other 2-hydroxy alkyltertiary alcohol aminedicarboxylic esters and salts thereof.

The present invention has been described, in conjunction with variousillustrations and embodiments thereof set forth in the. specification.However, it is evident that equivalents may be substituted for thepresent compounds and procedural steps, without departing from theprinciples of this invention or the spirit thereof. Those of skill inthe art will recognize what equivalents and substitutes are also withinthe scope of the present disclosure.

What is claimed is:

1. A compound having in the free acid form a formula selected from thegroupconsisting of and mixtures of (A) and (B) wherein 1. R is C; to Calkyl, 2. R isC to C alkyl or C -C alkylol, 3. R and R are alkylene of Cto C and 4. R represents the residue of a dicarboxylic acid and selectedfrom the group consisting of maleic, succinic, glutaric, tartaric,malic, adipic, diphenic and naphthalic acids. 2. Compounds in accordancewith claim 1, wherein the dicarboxylic acid is maleic acid. 3. Acompound having the formula

1. A COMPOUND HAVING IN THE FREE ACID FORM A FORMULA SELECTED FROM THE GROUP CONSISTING OF
 1. R1 IS C8 TO C24 ALKYL,
 2. R2 IS C1 TO C6 ALKYL OR C2-C6 ALKYLOL,
 2. R2 is C1 to C6 alkyl or C2-C6 alkylol,
 2. Compounds in accordance with claim 1, wherein the dicarboxylic acid is maleic acid.
 3. A compound having the formula
 3. R3 and R5 are alkylene of C2 to C6, and
 3. R3 AND R5 ARE ALKYLENE OF C2 TO C6, AND
 4. R4 REPRESENTS THE RESIDUE OF A DICARBOXYLIC ACID AND SELECTED FROM THE GROUP CONSISTING OF MALEIC, SUSSINIC, GLUTARIC, TARTARIC, MALIC, ADIPIC, DIPHENIC AND NAPTHALIC, ACIDS.
 4. R4 represents the residue of a dicarboxylic acid and selected from the group consisting of maleic, succinic, glutaric, tartaric, malic, adipic, diphenic and naphthalic acids. 